Week 7-Long Piston With Cam

Long Piston With Cam Simulation in Ansys Transient

Objective:

Simulate the Cam motion of the given model and infer the results by varying the frictional coefficients.

Briefing

The model consists of 3 parts :

• Cam follower
• CAM
• Cylinder

The follower is attached to a piston which moves inside the cylinder as the follower follows the CAM profile.

Procedure and Setup:

Materials :

Structural Steel is used for the parts. Except for the CAM follower, all other parts are given rigid stiffness behavior.

Contact Definitions:

The Frictional (case 2 and Case 3) and frictionless contact is defined between;

• Cam follower and CAM
• Cam follower and piston

Joint :

3 joints are defined in this case:

• The piston is fixed to the ground.

• The revolute joint is defined for the CAM

• A translational body-to-body joint is defined between the piston and the cylinder (mobile).

Meshing :

The contact surfaces are defined between the contact surfaces and face meshing of 3mm is done.

Boundary Conditions:

• The joint revolute joint is given to the CAM

Analysis Settings:

• 9 load steps are given to the model, with the minimum time step as 0.05 sec and the Maximum time step as 0.3 sec.

• two different case studies with frictional coefficients as 0.1 and 0.2.

Results and Case Study

Cases / Parameters	Equivalent Stress (Max Over the time)	Directional Deformation ( Y-Axis)	Equivalent Elastic Strain
Case 1	1704.8 MPa	50.8 mm	8.5727e-003 mm/mm
Case 2	1872.6 MPa	50.801 mm	9.4153e-003 mm/mm
Case 3	2092.2 MPa	50.801 mm	1.054e-002 mm/mm

• The equivalent stress developed in the cam follower is highest in case 3, with the highest frictional coefficient.
• The elastic strain developed in the model is highest in case 3 compared to the other cases.

The stress profile developed in the cam follower is similar for the cases with friction.

Case 1 Equivalent Stress of the cam follower:

Case 2 Equivalent Stress of the cam follower:

Case 3 Equivalent Stress of the cam follower: